How does work impact daily sleep quality? A within-individual study using actigraphy and self-reports over the retirement transition

This study examined how the cessation of work at retirement affects daily measures of actigraphy-measured and self-rated sleep quality. Time in bed or asleep and stress at bedtime were examined as potential mechanisms. In total 117 employed participants who were aged 60-72 years and planned to retire soon were recruited to the Swedish Retirement Study. Sleep quality was measured in a baseline week using accelerometers, diaries, and questionnaires. Subjective sleep measures were sleep quality, restless sleep, restorative sleep, getting enough sleep, estimated wake after sleep onset, difficulties falling asleep, too early final awakening, and difficulties waking up. Actigraphy measures were sleep efficiency, wake after sleep onset, and average awakening length. After 1 and 2 years, the measurements were repeated for the now retired participants. Daily variations in sleep quality before and after retirement were analysed using multilevel modelling, with time in bed or asleep and stress at bedtime as potential mediators. We found that several self-reports of sleep improved (e.g., +0.2 standard deviations for sleep quality and +0.5 standard deviations for restorative sleep) while objective sleep quality remained unchanged or decreased slightly with retirement (e.g., -0.8% for sleep efficiency). Increased time in bed or asleep and stress at bedtime accounted partially for the improvements in self-rated sleep quality at retirement. In conclusion, actigraph-measured and self-reported sleep quality do not change in concert at retirement, highlighting the interest of studying both outcomes. The main effects of retirement from work concern subjective experiences of recovery more than sleep quality per se.